Abstract
A new structure which has retractable seawall on the crown has been developed for the purpose of reducing the volume of overtopping by high waves and delaying the inundation time caused by tsunami, and wave basin experiments were conducted to verify the performance of this structure to mitigate tsunami and storm surge disaster.As a result, that the retractable seawall on the crown stood by the force of high waves were observed, and the overtopping ratio is less than 0.3 times compared with the common wave-absorbing caisson breakwater. As for tsunami, it is shown that using the materials which are more lightweight than general steel reinforced concrete for the retractable seawall, the structure can delay the inundation time.
